ASSOCIAÇÃO DE FUNGICIDAS QUÍMICOS E BIOLÓGICOS NO CONTROLE DE DOENÇAS E NA PRODUTIVIDADE DA SOJA

Abstract

Soybeans stand out as one of the most important crops in Brazilian agribusiness, with significant economic importance and a strategic role in various production chains. Despite continuous growth in productivity, the crop is vulnerable to various diseases that compromise its performance. Among the challenges faced are leaf diseases, whose damage reduces photosynthetic efficiency and directly affects crop yield. This study evaluated the effectiveness of the combination of chemical and biological fungicides in controlling these diseases and in soybean productivity through a field experiment conducted in the 2023/2024 harvest using the Olimpo cultivar. The experimental design was randomized blocks with seven treatments and four replicates, including different combinations of active ingredients in four distinct applications throughout the crop cycle. Variables such as disease incidence and severity, defoliation, productivity (bags/hectare), and thousand-grain weight were evaluated. The data were statistically analyzed based on analysis of variance and Tukey's test at 5%. The results indicated that treatments containing Bacillus pumilus in the first two applications, combined with the use of Chlorothalonil in the last applications, performed best in controlling target spot, resulting in lower severity and defoliation rates. For brown spot, there was no significant difference between the fungicide molecules evaluated and the control treatment. Regarding grain yield and weight, the same treatments with Bacillus pumilus and Chlorothalonil showed numerical advantages, although without statistically significant differences. It is concluded that the integration of bio-inputs and chemical fungicides is a promising alternative in soybean phytosanitary management, especially in the control of target spot, promoting agronomic gains and contributing to more sustainable agricultural practices. However, the need for further research under different disease pressure conditions is emphasized, in order to validate and expand the results obtained.